yashsingh1/xdaforums huggingface dataset:
[Nook Color General] a.fenderson:
Just to confirm: these are the same cards that you posted abbreviated benchmarks for in this previous post, right? Were the testing conditions between the two runs different in any potentially significant way?

I tried the following Android benchmark apps, testing my Kingston Class 4, 8GB card which CystalDiskMark reported thus:

Sequential Read : 4.418 MB/s
Sequential Write : 3.504 MB/s
Random Read 512KB : 4.407 MB/s
Random Write 512KB : 1.043 MB/s
Random Read 4KB (QD=1) : 1.528 MB/s [ 373.1 IOPS]
Random Write 4KB (QD=1) : 0.011 MB/s [ 2.7 IOPS]
Random Read 4KB (QD=32) : 1.652 MB/s [ 403.3 IOPS]
Random Write 4KB (QD=32) : 0.014 MB/s [ 3.3 IOPS]

1. SD Tools (doesn't describe its methodology, or have any options for that matter): 6.7 MB/s write, 14.0 MB/s read.

2. J Disk Benchmark 3.0 (does allow you to specify a write unit size, including 4KB, and file size, including 50 MB, and whether to test internal mem or the SD card, but otherwise doesn't detail methodology and no other options): 3.6MB/s write, 5.25 MB/s read.

3. System Benchmark (no control over or info on how the SD card test is run, and you have to wait for it to bench your entire system): 6.3 MB/s write, 7.4 MB/s read

If the results CrystalDiskMark are giving to all of us are anywhere near accurate, then none of these apps actually tests random small-block read or write. And that sucks.

I looked through a lot of other apps' descriptions, but none seemed very promising.

Another quick SD accessory review: the "SanDisk Special Edition microSDHC & M2 USB 2.0 Slim Card Reader With 4 Storage Slots - Retractable" (seller: BlueProton Consulting, fullfillment via Amazon). It's about 5 times as thick as a credit card, but otherwise matches the remaining two dimensions. It has storage-only slots to hold 2 microSD cards very securely, one M2 card (untested), and one SIM card (tested, holds well). In a pinch, a microSD card can be slotted into the SIM card slot and will hold fairly well, but not as well as the intended slots. There is one reader slot that accepts M2 or microSD, and while it's not the nice spring-eject type, it does hold the card securely and could also be used to store an SD card. The male, full-size USB interface comes out of the card with a slide-button that locks in the extended and retracted positions (press in to unlock), but it's just the piece with the contacts and so fits entirely into the mated port. A small green LED lights when the unit is plugged in, and blinks while reading or writing. I read and wrote via the reader several times, no problems--didn't benchmark the card via it, though. It's all plastic, and feels neither incredibly durable nor flimsy--it should last a while with care. Overall, I'm a fan. :-)
[Nook Color General] GTT1:
You are so right. I put Pulse on my SD with the transcend and that app causes no end of problem. Put it on the Sandisk 4gb class 2 and Pulse runs fine. Now it is the only program that seems to be a problem. Pulse is so good that I will probably keep the Sandisk in even though it is only 4gb.

Does Pulse work fine for those running CM7 of EMMC without FC's
[Nook Color General] zombieflanders:
Just to re-confirm, the Sandisk 8GB card to get from Amazon is this one from earlier in the thread?

SanDisk microSDHC 8GB Card with SD Adapter (SDSDQ-8192)
[Nook Color General] a.fenderson:
If you check the code box at the bottom of this posting, you'll see that several people in this thread have benchmarked SanDisk 8GB cards. I don't know where anyone else got their card. I have one myself, though, and I did buy it from Amazon, the listing that you linked, however:

1. Listings such as that one offer the item through multiple sellers (click on "22 new" or whatever to go to the page where all sellers are listed), and the default seller that happens to pop up any given time you go to the item listing page can be different, even 5 minutes later on the same computer--I've had it happen. I got mine from Digital Media Source, and...

2. The items sometimes differ from the listing. My most recent Amazon order included 6 SD cards from 5 different sellers: 2 unclassed cards, and 4 cards that were all listed as Class 2. Yet, for each of the four cards that was listed as Class 2, I received a Class 4: this may indicate that Class 2 cards are no longer entering the supply chain, but I know they can still be found at retail stores that stock SD cards but don't move a lot of them. The sellers on Amazon don't know enough to think of giving you a higher Class card than what was listed as anything other than an upgrade, but higher Class ratings may sometimes equate to lower small-block random writes.

Having said that, overall I was happy with my Amazon experience, but that's due in no small part to the fact that on a SanDisk card (which is the only brand I ordered), going from Class 2 to Class 4 doesn't seem to impact small-block random writes too horribly.
[Nook Color General] robot8:
Two different sets of cards actually.

Thanks for checking, it does confirm my suspicions that Pulse writes to the card in such a way that it would FC when the card chokes.
[Nook Color General] light_n_roses:
Hi all !

I got and htc HD2 and I'm running a thread very similar to this in order to find the best card for running android from the micro-sd here: http://xdaforums.com/showthread.php?t=1048649 . I was thinking that the best results was the random read and not the write because I was thinking tha OS need to read fast and not to write but it seems that I was wrong. Anyway I'm turning my interest to a sandisk microsd 16gb card but I don't know if take a class 2 or a class 4, do you have any suggest ? I have seen that there are many results for those to alternative in this thread but no one has specifieed if he has run the test of the 50 mb, 100 mb or 100 mb in the crystalmark, I'm specifing this because results can change in those 2 test, as far as I know the more realistic test are the 50mb and the 100 mb .

P.S. I have seen this micro sd : http://www.amazon.it/dp/B001F7AJKI/...ve=23390&creativeASIN=B001F7AJKI&linkCode=asn

but I don't know what the "HC" is that for, or better I think it's for "High capasity " but I don't know if it's better a sandisk microsd 16gb class 2 or a sandisk microsd HD 16gb class 2
[Nook Color General] a.fenderson:
@light_n_roses: I sent a reply to your PM, but wanted to address a couple of things in your post also.

In all my benchmarks I posted, I used the 50MB file size--I put this on the first two posts, but forgot to mention it after that. Also I always ran the 5x option so that it ran every test five times then averaged the results.

The small-block random writes does seem to be the determining factor for getting a good Android experience when installing the ROM on the card, but that's possibly because the small-block random reads are never 1/100th the speed of the sequential. In fact a quick glance at the first few benchmarks posted shows that almost all cards, whether they're listed as being good or bad to run Android from, have 4KB random read speeds of between 0.5MB/s and 5+MB/s--if we ever find a card with very poor 4KB random reads but good 4KB random writes (if they exist), those may also run Android poorly.

As for SD vs SDHC--you're right, it means High Capacity, and any card larger than 4GB is either High Capacity or it's in violation of specifications. For more info, see the Wikipedia entry on SD, especially Storage Capacity section and below. If your device is sdHC compliant, then it will accept any specifications-adhering card up to sdHC 32 GB size. SDXC cards can be larger, but most devices do not have official support for this type.
[Nook Color General] light_n_roses:
Hi !

Thanks for your info ! Non I have just need to decided if buy a 16 sandisk class 2 or 4 as it seems that class 2 has little better results, the results on first page are a little better than your also if the author of the thread doesn't specified if he runs the 50 mb test..
[Nook Color General] Taosaur:
I'll put forward the hypothesis that it's not necessarily true that "better 4KB random writes mean better performance as a CM7 boot drive," but perhaps only that "there is a minimum range of 4KB random write speed for adequate performance as a boot drive, beyond which few or no gains are seen." We don't have much to go on in terms of measuring real-world performance, but the reports we've seen really only support the claim that cards with 4KB r.w. below about .5 (maybe even .1 or .05) perform poorly as boot drives, in which case the difference between Sandisk c2 and c4 cards is negligible or non-existent, and one should go for the one with highest large sequential r/w that also maintains an adequate small r. w.

This hypothesis could probably be tested by benchmarking mid-class (c4 + c6) cards in search of one with small r. w. in the .05-.5 range and correspondingly improved large s. r/w. There may be no such card, of course--I don't think we've seen one yet. a.fenderson has benched some cards with small r. w. in that range--if they have correspondingly high large s. w., it may be worth testing their performance as boot drives. If they also have low large s. w., they're probably just crappy cards.

For practical purposes we would probably be better off identifying some 32GB cards that perform adequately as boot drives, rather than seeking the optimal SRW/LSRW ratio.
[Nook Color General] light_n_roses:
Hi Taosaur !

Honeslty what leave me doubful about sandisk 16 gc class 4 is the result on sequential read, here : " Random Read 4KB (QD=32) : 1.191 MB/s " , it seem a little low to me, considering that on front page we have this results for class 2 : "Random Read 4KB (QD=32) :___3.077 MB/s"
[Nook Color General] Taosaur:
You said sequential read and then posted random reads, and neither of those benchmarks have been found to correlate with performance as a boot drive. Many of the cards reported as performing poorly had similar random reads to those reported as performing well. Both class 2 and 4 Sandisk 16GB cards have been reported to perform very well (mine is unclassed, so 2).
[Nook Color General] GTT1:
I just tested out Racks Dualboot Phiremod / Honeycomb Image for SDcard thread and used my Transcend 8gb class 6.

I notice both of these ROMS run much slower than CM7 which zips along with the Transcend or my Sandisk 4gb class 2. One observation I made was that Pulse runs fine but slow on the Transcend without any forced closes as it did on CM7

I am for sure sticking with CM7 based on this test.
[Nook Color General] light_n_roses:
yeah sorry I was meaning random read as I have reported then. so you said that random read isn't important ?? I was thinkng the contrary..

Anyway at the endthe most importat thing to know it's just one, the sandisk 16 class 4 is good enough to run desire hd rom on my HD2 without lag ? I want a fast memory because with my actual card this is not possible at the moment, and considering the recent avaibility with sense 3.0 I suppose that I will need a card always faster !
[Nook Color General] Ravynmagi:
I must have the slowest Sandisk microSD card on the board. Geez.

I have an 8GB Sandisk C2 that I run CM7 on, it's a little slow, but everything seems very stable and I hadn't really had any complaints. But I wanted to use a 16GB card or more space.

Went to Fry's and bought a 16GB Patriot C10 and a 16GB Wintech C10. Tried CM7 on both and neither seemed very stable. Originally I thought the problem was I was trying to use CM7.02 on the the 16GB cards and I was still using CM7.0.0 on my 8GB card. So I blamed the problem on the newer version of CM7. But after reading this thread I wonder if it wasn't just the cards now.

I'm going to return the Wintech 16GB card and go pick up a Sandisk 16GB over at RadioShack.

4K Rd	4K Wr	Seq Rd	Seq Wr

Sandisk 8GB C2	3.920	0.025	21.776	6.561
Unknown 4GB C2	4.031	0.026	21.773	10.292
Patriot 16GB C10	4.319	0.014	18.882	12.213
Wintech 16GB C10	4.593	0.029	20.871	17.902

Sandisk 8GB C2

Sequential Read : 21.776 MB/s
Sequential Write : 6.561 MB/s
Random Read 512KB : 21.286 MB/s
Random Write 512KB : 2.001 MB/s
Random Read 4KB (QD=1) : 3.920 MB/s [ 957.1 IOPS]
Random Write 4KB (QD=1) : 0.025 MB/s [ 6.2 IOPS]
Random Read 4KB (QD=32) : 3.918 MB/s [ 956.6 IOPS]
Random Write 4KB (QD=32) : 0.033 MB/s [ 8.0 IOPS]

Unknown 4GB C2

Sequential Read : 21.773 MB/s
Sequential Write : 10.292 MB/s
Random Read 512KB : 21.273 MB/s
Random Write 512KB : 2.544 MB/s
Random Read 4KB (QD=1) : 4.031 MB/s [ 984.2 IOPS]
Random Write 4KB (QD=1) : 0.026 MB/s [ 6.4 IOPS]
Random Read 4KB (QD=32) : 4.050 MB/s [ 988.7 IOPS]
Random Write 4KB (QD=32) : 0.037 MB/s [ 9.0 IOPS]

Patriot 16GB C10

Sequential Read : 18.882 MB/s
Sequential Write : 12.213 MB/s
Random Read 512KB : 19.065 MB/s
Random Write 512KB : 1.484 MB/s
Random Read 4KB (QD=1) : 4.319 MB/s [ 1054.4 IOPS]
Random Write 4KB (QD=1) : 0.014 MB/s [ 3.5 IOPS]
Random Read 4KB (QD=32) : 4.532 MB/s [ 1106.4 IOPS]
Random Write 4KB (QD=32) : 0.030 MB/s [ 7.2 IOPS]

Wintech 16GB C10

Sequential Read : 20.871 MB/s
Sequential Write : 17.902 MB/s
Random Read 512KB : 20.696 MB/s
Random Write 512KB : 2.687 MB/s
Random Read 4KB (QD=1) : 4.593 MB/s [ 1121.4 IOPS]
Random Write 4KB (QD=1) : 0.029 MB/s [ 7.0 IOPS]
Random Read 4KB (QD=32) : 4.904 MB/s [ 1197.2 IOPS]
Random Write 4KB (QD=32) : 0.036 MB/s [ 8.7 IOPS]
[Nook Color General] light_n_roses:
you have very poor results in the Random Write 4KB even with the sandisk class2 , that's strange maybe your card reader isn't that great ! How android runs with the sandisk class 2 ?
[Nook Color General] I Am Marino:
So can someone explain this to me in terms to someone not familiar with SD cards in terms of these benchmarks and such?

and

Which card should I go to the store and buy based off this thread for optimal performance off the SD card?
[Nook Color General] light_n_roses:
you need a sandisk class 2 ...

By the way anyone can help me to discover which class is this micro sd : http://www.monclick.it/schede/prodo...-016G-E11M&utm_campaign=memorie micro sd card ? It has the same code : SDSDQM-016G-B35 of the one sold on amazon which is know to be a class 4 even if it's marked as a class 2 ( this on amazon, the one that I have linked has no class mark, just the photo but I don't think that it's accurate ).
[Nook Color General] chinly43:
As has been said earlier in the thread, anecdotal evidence suggests that a higher small-block write speed produces better-performing (in terms of things like a lack of force-closes, smoothness, etc) ROMs when run from the sdcard. It's been guessed that this is due to the need of the ROM to do a lot of quick access when doing regular tasks like opening apps and such. Higher-class cards tend to sacrifice this type of speed in favor of faster large-block read/write speed, which accesses/transfers large files faster.

As such, you'll likely be happiest with cards near the top of the list in this post: http://xdaforums.com/showpost.php?p=13662784&postcount=76.
[Nook Color General] I Am Marino:
So Sandisk Class 2 or 4 with 8 or 16GB.

Thanks.
[Nook Color General] nksharp:
Would a higher class sandisk be better or is there something special about this class that makes it better suited for the CN?
[Nook Color General] Taosaur:
Class 2, class 4 and unclassed Sandisks in 8GB and 16GB seem to be our best bet, but there's some variability even among cards of the same make and class. You can see the benchmarks throughout this thread for yourself. Class itself doesn't reference any benchmarks that are meaningful for use as a system drive.
[Nook Color General] trjcasper:
OMG thank you for this post/thread. I was totally bummed about my NC not running very well booting CM7 from sd. My experience was equal to that described so accurately by the OP.

I benchmarked 5 different sd cards I had around the house. They all were class 4 or above. They all sucked. Ran to the store (office depot) and massively overpaid :o for the last class 2, 8GB on the shelf. Speed home, tear into the stupid blister plastic it was packed in, and run a bench mark test. IT'S TRUE! They do have a better small block random write speed. Quickly image the card and install CM7 nightly. Boot. OMG it works smooth! It works just like a real operating system running from emmc. THANK YOU
[Nook Color General] dweezilz:
Also wanted to report that with my new Sandisk class 2 (8 & 16GB) card, CM7 is running smooth as silk! No errors, FC's, corruption, web browser lag, menu lag, video choppiness. So far after a week, it's all good. Who would have thought that a technically slower card would be so much better for this than a class 10 card. Now I'm pissed I spent so much on the class 10 card!! ha!:p
[Nook Color General] threebeers:
Ratshack Class 4 16 GB Sandisk okey-dokey after a week of use. Replaced a Transcend 8gb Class 6 with many forced closes.

Sandisk is giving some FCs too, especially on games. But I now have 400 Apps on the thing (everything over 2GB has been moved to /SD other than browsers and Pulse), so maybe not suprising. Advanced Task Killer seems to resolve the problem when it arises.

Question for the gurus: Is there a diagnostic/cleanup app I can run, say off Spare Parts, that would help with the above?
[Nook Color General] polarborn:
SD Cards

Had been using a Sandisk 16G Class 2 - worked great so.. thought I would try the Transcend 16Gm Class 6 - sucks, forced closures, seemed no faster when it worked. Just ordered Sandisk 32G Class 4 - I'll let you know.
[Nook Color General] arwild01:
Another Sandisk 8GB C4 Test

Stopped by the Radio Shack near my house today. They had one 8GB Sandisk card left, a class 4. It didn't have a price on it. When I inquired about the price with a sales clerk it came up with two numbers $17 and $12. This confused her so she pulled over the manager and he explained, "Oh it's $17 but I can mark it down to $12". So I immediately chimed in, "If you'll sell it to me for $12 I'll buy it." I don't know if he would do it again or if he just felt caught but he said "sure".

Here's my result using my Dell's build in card-reader:

-----------------------------------------------------------------------
CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
Crystal Dew World : [I]url removed[/I]
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

Sequential Read : 8.013 MB/s
Sequential Write : 5.401 MB/s
Random Read 512KB : 7.975 MB/s
Random Write 512KB : 1.489 MB/s
Random Read 4KB (QD=1) : 3.531 MB/s [ 862.0 IOPS]
Random Write 4KB (QD=1) : 1.468 MB/s [ 358.3 IOPS]
Random Read 4KB (QD=32) : 3.579 MB/s [ 873.8 IOPS]
Random Write 4KB (QD=32) : 1.369 MB/s [ 334.3 IOPS]

Test : 50 MB [F: 0.0% (0.0/7572.0 MB)] (x5)
Date : 2011/05/17 19:55:17
OS : Windows 7 Ultimate Edition SP1 [6.1 Build 7601] (x64)
[Nook Color General] arwild01:
I found another 8GB class4 I already own. Not 100% sure of the make, but as I believe it came with my Samsung Moment... I'm willing to bet Samsung.

-----------------------------------------------------------------------
CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
Crystal Dew World : url deleted
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

Sequential Read : 15.926 MB/s
Sequential Write : 7.652 MB/s
Random Read 512KB : 15.849 MB/s
Random Write 512KB : 1.794 MB/s
Random Read 4KB (QD=1) : 5.681 MB/s [ 1387.0 IOPS]
Random Write 4KB (QD=1) : 0.017 MB/s [ 4.2 IOPS]
Random Read 4KB (QD=32) : 5.567 MB/s [ 1359.0 IOPS]
Random Write 4KB (QD=32) : 0.017 MB/s [ 4.1 IOPS]

Test : 50 MB [F: 2.9% (216.9/7598.0 MB)] (x5)
Date : 2011/05/17 22:41:43
OS : Windows 7 Ultimate Edition SP1 [6.1 Build 7601] (x64)

I think I'll use the Sandisk, thankyouverymuch
[Nook Color General] ahfo:
i also have a Kingston Class 4 4gig, i works well.
[Nook Color General] a.fenderson:
re: Windows Phone certified microSD cards.

I inquired at the AT&T Mobile store in a larger city yesterday, and was told they were sold out of these, but eventually we did actually find one on the shelf. It was a SanDisk Class 4, 8GB card and had the little Windows Phone logo in the upper-right corner. It was marked $32.00 exactly, and had a plastic case and SD adapter. I don't know to what degree, if any, these cards have actually been tested to perform as OS drives, but I couldn't bring myself to pay $32.00 plus retail tax for a card that, other than the Windows Phone logo on the package, I can get for between $10 and $20 shipped from Amazon.
[Nook Color General] Taosaur:
I had the same experience calling around after uSD readers today--they start at $13 for a dedicated uSD reader of questionable quality that I could get for $4-6 online. I've been making due without a reader up until now (see sig), but I want to wipe my verygreen image and swap in racks' HC/Phiremod dual-boot, and I'm hesitant to try formating my SD over USB when even EASEUS can only see the boot partition.

I ended up grabbing that Sandisk multi-reader/carrier you wrote up earlier in the thread: something I'll actually be glad I have at some point down the road.
[Nook Color General] pchoi94:
OH

MY

GOD

THANK YOU^google

When I first read posts here and there about the SD card affecting performance, I said to myself, "Bah, what are these people talking about!"

But countless force closes and hours of added up multi-second-delays later I am now seeing the light!

After reading this thread I decided to test my kingston 16GB class 2 sd card (I'm booting CM7 off SD) and got 0.030 MB/s on the 4K Random Write QD32 test. I promptly ventured out to Radio Shack and got a sandisk 16GB class 4 card (luckily still on sale for $29.99) and hurried home to run my test. 0.834 MB/s on the 4K Random Write QD32 test. It's still about half of what some of you were getting, but that's about 27.8 times faster than the kingston.

It used to take minutes to hours to install each tiny little app from the market. When I booted up and restored all of my apps (all 30 or 40 from the market at the same time) it took literally around 5 minutes.

When I used to browse sites on the native browser there used to always be a delay when clicking on links, going to sites, etc. Now some pages literally load so fast it doesn't get a chance to display the progress bar!!!

No more force closes. Everything feels INSTANT.

THANK YOU THANK YOU THANK YOU!!!!!
[Nook Color General] CastellFaber:
Thanks for the analysis. I was just about to select a SD vendor.
[Nook Color General] omghahalol:
Multi-card test

Here are my results on Three cards. I am using the five (5) iteration 50MB test, is that test a good measure of performance or should I increase the size. I aimed for as small as possible to mimic small system reads and writes.

[B]Transcend 16GB Class 6 [/B]
Sequential Read : 18.474 MB/s
Sequential Write : 16.788 MB/s
Random Read 512KB : 18.425 MB/s
Random Write 512KB : 2.176 MB/s
Random Read 4KB (QD=1) : 3.872 MB/s [ 945.2 IOPS]
Random Write 4KB (QD=1) : 0.028 MB/s [ 6.7 IOPS]
Random Read 4KB (QD=32) : 4.029 MB/s [ 983.6 IOPS]
Random Write 4KB (QD=32) : 0.037 MB/s [ 8.9 IOPS]
Test : 50 MB [G: 11.3% (1.7/14.9 GB)] (x5)

[B]Transcent 8GB Class 6[/B]
Sequential Read : 18.973 MB/s
Sequential Write : 8.881 MB/s
Random Read 512KB : 18.758 MB/s
Random Write 512KB : 1.738 MB/s
Random Read 4KB (QD=1) : 3.546 MB/s [ 865.7 IOPS]
Random Write 4KB (QD=1) : 0.018 MB/s [ 4.3 IOPS]
Random Read 4KB (QD=32) : 3.664 MB/s [ 894.6 IOPS]
Random Write 4KB (QD=32) : 0.033 MB/s [ 8.1 IOPS]
Test : 50 MB [G: 18.1% (12.6/69.5 MB)] (x5)

[B]Sandisk 2GB Class 2[/B]
Sequential Read : 10.692 MB/s
Sequential Write : 6.428 MB/s
Random Read 512KB : 10.613 MB/s
Random Write 512KB : 1.218 MB/s
Random Read 4KB (QD=1) : 3.318 MB/s [ 810.1 IOPS]
Random Write 4KB (QD=1) : 0.012 MB/s [ 2.9 IOPS]
Random Read 4KB (QD=32) : 3.423 MB/s [ 835.7 IOPS]
Random Write 4KB (QD=32) : 0.021 MB/s [ 5.1 IOPS]
Test : 50 MB [G: 3.1% (3.7/118.1 MB)] (x5)
[Nook Color General] a.fenderson:
I'm not sure, but that's exactly what I used on all my benchmarks.